Index funds are an easy way to diversify your retirement funds, and they’re about as cheap as it gets.

At Fidelity and Vanguard, you pay just a tenth of one percent for a bunch of basic index funds. Most other investment companies charge 1 to 1 ½ percent for doing the exact same thing.

There are plenty of funds to choose from: I own a large cap index fund, a small cap fund, an international fund and a bond fund. With four index funds, I’ve cut way back on my risk with returns that will beat 85 percent of managed mutual funds. I can even buy sector index funds.

Check out how different index funds have performed – and how much they cost – at Morningstar.com.